/**
 * javascript map
 */
function Map() {
    this.elements = new Array();

    /**
     * 获取MAP元素个数
     * @return {}
     */
    this.size = function () {
        return this.elements.length;
    }

    /**
     * 判断MAP是否为空
     * @return {}
     */
    this.isEmpty = function () {
        return (this.elements.length < 1);
    }

    /**
     * 删除MAP所有元素
     */
    this.clear = function () {
        this.elements = new Array();
    }

    /**
     * 向MAP中增加元素（key, value)
     * @param {} _key
     * @param {} _value
     */
    this.put = function (_key, _value) {
        var isContainKey = false;
        for (var i = 0; i < this.elements.length; i++) {
            if (this.elements[i].key == _key) {
                isContainKey = true;
                this.elements[i].value = _value;
                break;
            }
        }
        if (isContainKey == false) {
            this.elements.push({
                key: _key,
                value: _value
            });
        }
    }

    /**
     * 删除指定KEY的元素，成功返回True，失败返回False
     * @param {} _key
     * @return {Boolean}
     */
    this.remove = function (_key) {
        var bln = false;
        try {
            for (var i = 0; i < this.elements.length; i++) {
                if (this.elements[i].key == _key) {
                    this.elements.splice(i, 1);
                    return true;
                }
            }
        } catch (e) {
            bln = false;
        }
        return bln;
    }

    /**
     * 获取指定KEY的元素值VALUE，失败返回NULL
     * @param {} _key
     * @return {}
     */
    this.get = function (_key) {
        try {
            for (var i = 0; i < this.elements.length; i++) {
                if (this.elements[i].key == _key) {
                    return this.elements[i].value;
                }
            }
        } catch (e) {
            return null;
        }
    }

    /**
     * 获取指定索引的元素（使用element.key，element.value获取KEY和VALUE），失败返回NULL
     * @param {} _index
     * @return {}
     */
    this.element = function (_index) {
        if (_index < 0 || _index >= this.elements.length) {
            return null;
        }
        return this.elements[_index];
    }

    /**
     * 判断MAP中是否含有指定KEY的元素
     * @param {} _key
     * @return {}
     */
    this.containsKey = function (_key) {
        var bln = false;
        try {
            for (var i = 0; i < this.elements.length; i++) {
                if (this.elements[i].key == _key) {
                    bln = true;
                    break;
                }
            }
        } catch (e) {
            bln = false;
        }
        return bln;
    }

    /**
     * 判断MAP中是否含有指定VALUE的元素
     * @param {} _value
     * @return {}
     */
    this.containsValue = function (_value) {
        var bln = false;
        try {
            for (var i = 0; i < this.elements.length; i++) {
                if (this.elements[i].value == _value) {
                    bln = true;
                    break;
                }
            }
        } catch (e) {
            bln = false;
        }
        return bln;
    }

    /**
     * 获取MAP中所有VALUE的数组（ARRAY）
     * @return {}
     */
    this.values = function () {
        var arr = new Array();
        for (var i = 0; i < this.elements.length; i++) {
            arr.push(this.elements[i].value);
        }
        return arr;
    }

    /**
     * 获取MAP中所有KEY的数组（ARRAY）
     * @return {}
     */
    this.keys = function () {
        var arr = new Array();
        for (var i = 0; i < this.elements.length; i++) {
            arr.push(this.elements[i].key);
        }
        return arr;
    }
}
